At the moment the altcoin market cap (excluding btc) seems not to show the real situation. Indeed the market cap stays pretty high while . I honestly can not find a real explanation but the following two
1 - alt lost a lot compared to btc, not in absolute levels
2 - many alts are born every day, and the new one market cap is added to the old one keeping the marketcap high overall, but the "top 100" alts are suffering a lot.
Do you have any explanation? Let me know in the comment section!